【摘要】 目的探讨衰老与生物分子（ＤＮＡ、胶原蛋白）交联损伤的关系。方法以Ｗｉｓｔａｒ系老年大鼠（１８月龄）及青年大鼠（５月龄）为观察对象，取鼠肝提取ＤＮＡ，测定其熔解温度和增色效应，以反映ＤＮＡ交联损伤与衰老的关系；取鼠尾腱分别测定尾腱胶原纤维热收缩起始温度、胶原蛋白含量及可溶性胶原含量以反映胶原纤维交联损伤与衰老的关系。结果老年鼠肝ＤＮＡ熔解温度（７４．３±１．０℃）和增色效应（１．４５±０．０８）均高于青年鼠（分别为７３．２±１．１℃及１．４２±０．０３），其中熔解温度的差异有显著性（Ｐ值＜０．０５）；老年鼠尾腱胶原纤维热收缩起始温度（６７．２±１．６℃）与胶原蛋白含量（６１３．６±７４．６μｇ／ｍｇ）均高于青年鼠（分别为６４．１±２．３℃及５２９．７±４６．３μｇ／ｍｇ），差异均有显著性（Ｐ值＜０．０１）；老年鼠可溶性胶原含量（５０．５±３．３μｇ／ｍｇ）低于青年鼠（５１．５±３．８μｇ／ｍｇ），差异无显著性。结论大鼠衰老后，ＤＮＡ交联和胶原纤维交联均增加更多还原

【Abstract】 Objective To explore the relation between aging and the cross linkage damage of biological molecules(DNA, protein).Metbod Old (18 months) and young(5 months) rats of Wistar strain were used and DNA was prepared from the liver of the tats. The melting temperature(Tm)and the hyperchromic effect of DNA were measured. In addition, the thermal contraction temperature, the collagen deposition capacity and the soluble collagen content in caudal tendon were assaied to explore the relation between aging and the cross linkage damage in collagen.Results The Tm(73.2 ±1.1℃)and the hyperchromic effect (1.42±0.08) of hepatic DNA in young rats were lower than those in old rats (74.3±1.0℃,1.45±0.03).the difference of Tm between old and young rats was significant(P<0.05).The thermal contraction temperature(67.2±1.6℃) and the collagen deposition capacity(613.6±74.6μg/mg)in caudal tendon of old rats were higher than those of young rats (64.1± 2.3℃,529.7±46.3μg/mg) (P<0.01). The soluble collagen content in caudal tendon of young rats (51.5±3.8μg/mg) was a little higher than that of old rats (50.5±3.3μg/mg) (P>0.05).Conclusions These results suggest that the cross linkage damage of DNA and collagen increase in old rats.更多还原